JPS591543B2 - automatic screw tightening device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic screw tightening device.

The purpose is to provide a device that can always tighten screws in an optimal state. 2. Description of the Related Art Conventionally, for example, in a manufacturing factory for television receivers, the work of attaching a back plate to a cabinet is automatically performed using an automatic screw tightening device.

If this type of cabinet is made of wood and the back plate is also made of wood, it is quite difficult to optimally tighten the screws with an automatic screw tightening device. In other words, a method is usually used in which the tightening torque of the driver is kept constant, and the screwdriver rotates and screws are engaged to stop the driver's rotation when the torque reaches a certain value, but due to the hardness of the wood. Since there are variations in each type of wood, if the wood is hard, the driver will stop before the screw head completely contacts the backing board, and the backing board will be in a floating state.On the other hand, if the wood is soft, the screw will rotate to the required level. As a result, the screws would spin idle in the wood, making it impossible to secure them firmly. The present invention improves the above-mentioned conventional drawbacks and provides a device that can always obtain a normal screw tightening condition regardless of the hardness of the object to be attached. Explain using.

Figure 1 shows an external view of the automatic screw tightening device.

A wooden cabinet 2 placed on a pallet 1 moves on a conveyor 3 and enters an automatic screw tightening device. The cabinet 2 that continues to move is the X reference body 4 that obstructs the path.
It stops together with pallet 1. Subsequently, the Y direction and Z direction are also determined by the means shown in FIG. 2, and the position of the cabinet 2 relative to the automatic screw tightening device is regulated. As shown in FIGS. 2A and 2d, the cabinet 2 is first connected to the X reference body 4. A pair of Y reference bodies 5 and Y regulators that do not impede the forward movement and protrude from the left and right sides of the cabinet 2 from a direction perpendicular to the moving direction of the conveyor 3 and stop at a fixed position, as shown in FIG. 2B and eVC. Body 6 toyo! ). The position of the cabinet 2 in the Y direction is regulated.

Next, as shown in FIGS. 2C and 2F, the X regulating body 7 protrudes from the surface facing the X reference body 4. The position in the x direction is regulated by sandwiching the cabinet 2. Further, as shown in Fig. 2g, the pallet 1 rises due to the rise of the lipter 8 and stops at the positions of the four Z regulating bodies 9 installed at the same height.
The position of the direction is regulated. Due to the series of operations above, the cabinet 2 is completely regulated in the X, Y, and Z directions. Next, move on to tightening the screws. The screws are tightened by driving the cylinder 10. Driver fixing frame 11 connected to cylinder 10 of No. 2
moves in the two directions of the cabinet.

A driver unit 1 is attached to the tip of the driver fixing frame 11.
2 is attached. At this time, the screw supply section 1 has already been
A screw from 3 is force-fed inside the single-loose hose 14 and is located at the tip 15K of the driver 12. A motor 17 is attached to the rear end of the driver unit 12.
This motor 17 starts rotating after the positioning of the cabinet 2 is completed. The screw 16 moves forward while rotating together with the driver bit 18. Cabinet 2K has the back plate 20 temporarily fixed in advance. The tip of the screw 16 contacts the back plate 20. The screws 16 are driven into the back plate 20 by the rotational force of the motor 17. As the rotation continues, the screw 16 is also screwed into the cabinet 2. , a position detector 21 such as a leaf switch is installed in the driver unit 12 at a position slightly away from the driver bit 18.
It is fixedly installed. Therefore, the position detecting body 2
1 moves forward at the same time as the driver unit 12 moves forward, and is provided so that the tip position of the position detecting body 21 and the tip position of the driver bit 18 are approximately equal to each other. The position detecting body 21 has its tip connected to the back plate 2.
This is to stop the rotation of the motor 17 when the screw 16 is in contact with the screw 16. This screw 1
When the screw head 19 of No. 6 comes into contact with the back plate 20, the tip of the position detection body 21 also comes into contact with the back plate 20. The leaf switch of this position detector 21 is disconnected. Stop the power supply voltage supply to the motor 17 to stop the rotation of the motor 17, and then screw the screw 1.
This is to stop the screwing of 6.

At this time, the driver fixing frame 11 also stops moving forward. Now you have finished tightening the screws.Driver unit 12
and the driver fixing frame 11 move backward. If there are multiple screws to fix. Move the cabinet 2 above and set new positioning in the XYZ directions. All you have to do is tighten the screw again in the same way as above. After all the screws have been tightened, the cabinet moves along with the pallet 1 on the conveyor 3 and exits the device. Although the above embodiment describes a cabinet, the present invention is not limited to this. Needless to say, it can be applied to other objects.

According to the present invention as shown above. When automatically tightening screws with a machine. The position of the object to be mounted can be determined accurately in all directions (X, Y, and Z) by sandwiching the object. Furthermore, detection of completion of screw tightening is possible. A separately installed position detector detects that the screw head has come into contact with the object to be installed. Based on this detection output, the rotation of the motor that rotates the driver is stopped, and the movement of the driver is also stopped.
．． Therefore, safety is high (and there is no variation in screw tightening). Screws can be screwed together correctly and securely regardless of the hardness or softness of the object to be attached. A good fixing state can be obtained.

[Brief explanation of drawings]

Figure 1 is a perspective view of an automatic screw tightening device according to an embodiment of the present invention. Figures 2A, b, and c are plan views showing the operating state of the device. Figures 2D, e, f, and g are front views showing the operating state of the device. FIG. 3 is an enlarged sectional side view of the main parts of the device. 2... Cabinet. 3... Conveyor. 4...X reference body. 5...Y reference body. 6...Y regulator. 7...X regulator. 8... Sokta. 9...Z regulation body. 1
0...Cylinder. 12...Driver unit. 16...Bis. 17...
motor. 18... Driver bit. 19・
...screw head, 20...back plate.

Claims (1)

[Claims] 1. A transport means for placing and transporting the object to be attached on a pallet, an X reference body that stops the movement of the object to be attached together with the pallet and positioning the object in the traveling direction,
An X regulating body that positions the attached body in the X direction by abutting the attached body whose movement has been stopped by the reference body from the opposite direction to the X reference body and positioning the attached body in the X direction by sandwiching the attached body between the X reference body and the attached body. A Y reference body and a Y regulating body that position the object in the Y direction across the object from the Y direction perpendicular to the direction of movement of the object, and a lifter that positions the object in the Z direction that is the height direction of the object. A Z regulating body, a driver that rotates and moves toward the object to be attached after positioning the object to be attached, and a motor that rotates the driver, and the motor is installed so that its tip position is approximately equal to the tip of the driver. a position detection body that moves together with the driver, and when the head of the screw comes into close contact with the object to be installed by the driver, the position detection object comes into contact with the object to be installed and generates a control output to rotate the motor. An automatic screw tightening device configured to stop the driver and stop the movement of the driver.